High efficiency color liquid crystal display

ABSTRACT

A liquid crystal display has a light source unit and a liquid crystal panel unit, and includes a unit for emitting rays having wavelengths corresponding to the primary colors in respective three directions, a lens group unit provided on the light incident side of the liquid crystal panel unit; and a lens group unit provided on the light emitting side of the liquid crystal panel unit and having a focal plane disposed outside the liquid crystal panel unit. Angles of propagation directions of emitted rays of the primary colors are made different from one another by the primary-colors three direction emitting unit, the rays of the primary colors are introduced into respective picture elements corresponding to the primary colors by the panel-light incident side lens group unit, and the propagation directions of the emitted rays of the primary colors are made to substantially coincide with one another by the panel-light emitting side lens group unit.

CROSS-REFERENCE TO RELATED APPLICATION

This is a division of application Ser. No. 08/104,479 filed on Jul. 28,1993, now U.S. Pat. No. 5,623,348.

BACKGROUND OF THE INVENTION

The present invention relates to a high efficiency color liquid crystaldisplay, and more particularly to a liquid crystal display having a highlight utilization efficiency.

In a prior art color liquid crystal panel, a large number of sets ofpicture elements are formed with picture elements of the primary colorsof R (red), G (green) and B (blue) constituting each set. The pictureelements corresponding to the respective primary colors containcorresponding pigments. Therefore, when applying white light to thecolor liquid crystal panel, the picture elements corresponding to R, Gand B transmit only rays having wavelengths corresponding to thesepigments. As a result, the efficiency of utilizing light is degradedtheoretically to about 1/3 or less because each one pigmentcorresponding to the associated primary color absorbs the rays havingwavelengths corresponding to the other two primary colors. Actually,since the pigments do not have ideal characteristics, the efficiency ofutilizing light is degraded to about 1/5.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide means forincreasing the efficiency of utilizing light of a color liquid crystalpanel up to about 3 times as large as that of the prior art one.

It is another object of the present invention to provide a projectiondisplay having excellent light utilization efficiency to which theabove-mentioned means is applied.

In order to attain the above-mentioned objects, the fundamentalembodiment of the present invention includes:

(a) liquid crystal panel means and light source means for emittingsubstantially parallel white light having a finite divergence angle ω;

(b) three-direction means for emitting rays having wavelengthscorresponding to the primary colors in three respective directions;

(c) first lens group means provided at the light incident side of thepanel means; and

(d) second lens group means provided after the first lens group means.

Each lens group means may be replaced with lenses arranged in a matrix.

The three-direction means serves to decompose incident white light fromthe light source means into primary color components and to emit rayshaving wavelengths corresponding to the primary colors in threerespective different directions. In this connection, an angle φ betweenthe three directions taken two at a time is made larger than thedivergence angle ω.

The first lens group means has the function of making the threedifferent directions correspond to the positions of respective ones ofthe picture elements of the primary colors which are included in theliquid crystal panel. Therefore, only the rays having wavelengthscorresponding to R, G and B are made incident on the picture elementscorresponding to R, G and B, respectively. As a result, the efficiencyof utilizing light can be increased up to 3 times as large as that ofthe prior art.

On the other hand, the second lens group means has the function ofchanging the three different directions to substantially one direction.Therefore, the directions of the emitted rays having wavelengthscorresponding to the primary colors can be made to substantiallycoincide with one another. As a result, it is possible to provide abright and beautiful color image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic horizontal sectional view showing the fundamentalembodiment of the present invention;

FIG. 2 is a schematic horizontal sectional view showing the main partsof another embodiment of the present invention;

FIG. 3 is a schematic horizontal sectional view showing the main partsof still another embodiment of the present invention;

FIG. 4 is a schematic horizontal sectional view showing the main partsof yet another embodiment of the present invention;

FIG. 5 is a schematic horizontal sectional view showing a liquid crystalpanel in the embodiment shown in FIG. 4;

FIG. 6 is a schematic perspective view showing an external form of aprojection lens used in the embodiment shown in FIG. 4;

FIG. 7 is a schematic horizontal view showing a direct view display asanother embodiment of the present invention;

FIG. 8 is a vertical sectional view showing the details of a liquidcrystal panel used in the embodiment of FIG. 7;

FIG. 9 is a perspective view showing the detailed construction of adirect view display constituting another embodiment of the presentinvention;

FIG. 10 is a schematic sectional view of a liquid crystal displayconstituting a variation of the fundamental embodiment of the presentinvention; and

FIG. 11 is a schematic sectional view showing another variation of thefundamental embodiment of the present invention shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

When disclosing the present invention hereinafter, for the sake ofmaking the understanding easy, it is assumed that a value of therefractive index n of a liquid crystal panel and various lens media is1.5. In addition, a liquid crystal panel, the size of which is 10",i.e., 200 mm wide×150 mm high, is taken by way of example to describethe preferred embodiments. In this case, the number of picture elementsis about 640×3 horizontally and about 480 vertically. The horizontalpitch of the picture elements is 0.1 mm and the vertical pitch thereofis 0.3 mm. But, it should be noted that since a proportional dimensionalchange can be made without affecting the essence of the optical system,the present invention is not limited to the above numerical example.

FIG. 1 is a horizontal sectional view showing the fundamental embodimentof the present invention. In the figure, the reference numeral 1designates light source means for emitting substantially parallel whitelight, which is well known. Then, it is assumed that a light divergenceangle of the light source means is ω (when describing the numericalexample of the present invention, the description is given with respectto the specific case where a value of ω is about 0.05 radian). The lightdivergence angle represents an error or dispersion of parallelism of theemitted rays. The reference numeral 2 designates three-direction meansfor emitting rays having wavelengths corresponding to the primary colorsin three respective different directions, which is constituted by threesheets of mirrors. The reference numeral 3 designates a mirror forreflecting red rays, the reference numeral 4 designates a mirror forreflecting blue rays, and the reference numeral 5 designates a mirrorfor reflecting green rays. The red-rays reflecting mirror 3 transmitsboth the green rays and the blue rays. The blue-rays reflecting mirror 4transmits both the red rays and the green rays. These reflecting mirrorscan be realized by the well known dichroic mirror technology. An anglebetween the reflecting mirrors 3, 4 and 5 taken two at a time is 0.5 φ.The rays after the reflection by the respective mirrors are illustrateddistinctively. That is, R (red), B (blue) and G (green) are respectivelyrepresented by a dashed line, a solid line and a corrugated line. Anangle between the reflected rays taken two at a time is, as shown in thefigure, φ. It is assumed that a value of φ is larger than that of ω.

The reference numeral 6 designates lenticular lens means arranged on thelight incident side of the panel. This lenticular lens means 6,constituting an example of the first lens group means referred to in thesummary of the invention, is arranged in such a way that its focal planecoincides in position with a plane on which the picture elements of theliquid crystal panel are arranged. Although in the figure, only threelens elements are illustrated for the sake of simplicity, the number oflens elements is actually equal to the number of sets of R, G and Bpicture elements. The reference numeral 7 designates the pictureelements. The reference numeral 8 designates lenticular lens means,constituting an example of the second lens group means referred to inthe summary of the invention, arranged on the light emitting side of thepanel. A focal plane of the lenticular lens means 8 is made to coincidewith a light incident surface of the lenticular lens means 6. Thedescription of the structure of the present invention has beencompleted. Next, the operation of the present invention will bedescribed.

The emitted rays from the three-direction means 2 are made incident onthe light incident side lenticular lens means 6. Then, the rays of R, Gand B are directed toward the respective picture elements of R, G and B.Therefore, there is no need for adding any pigments to the pictureelements.

In each picture element, the amount of light transmitted therethrough iscontrolled based on the principle of the liquid crystal display. But, itshould be noted that since the principle of the liquid crystal displayitself is well known, only the picture elements are illustrated in thefigure and other constituent elements are omitted.

With respect to the rays of the primary colors after passing through therespective picture elements, a difference in angle between the rays ofthe primary colors taken two at a time is cancelled by the lightemitting side lenticular lens means 8. For example, the rays of R, G andB, which have been made incident at angles of +φ, 0 and -φ on thecentral part of the lens means 6, respectively, become parallel rayseach having 0 degrees therebetween after emission from the lens means 8.The parallel rays are designated by the reference numeral 9. Thereference numeral 10 represents that the rays which have been madeincident on the end part of the lens means 6 are emitted from the lensmeans 8 in the form of oblique parallel rays. Since the focal plane ofthe lens means 8 is made to coincide with the light incident surface ofthe lens means 6, the direction of the emitted rays from the lens means8 is dependent only on the incident position of the rays on the lensmeans 6 and is independent of the incident direction thereof. Therefore,it is possible to make the directional characteristics of the emittedrays of the primary colors coincide with one another. As a result, abright and beautiful image can be reproduced.

Numerical examples of the lenticular lens means will be described indetail as preferred embodiments so that a person of ordinary skill inthe art can utilize the present invention with ease.

A first embodiment is shown in FIG. 2. In the figure, there is shown thespecific case where the value of φ is set 3 times as large as that of ω(0.05 radian), a focal length f1 of the light incident side lenticularlens means 6 is 1 mm, and a focal length f2 of the light emitting sidelenticular lens means 8 is 1.11 mm. In order to remove sphericalaberration of each of the lenticular lens means, the profile of each ofthe lenticular lens means may have an elliptical configuration in whichthe eccentricity thereof is equal to the inverse of the refractive indexn.

Incidentally, in the present invention, the following relationship isestablished among the horizontal pitch P1 of the picture elements, thefocal length f1 (=1 mm) and the difference φ in angle between theincident rays taken two at a time.

    f1·φ=n·P1 . . .                      (1)

Further, the radii r1 and r2 of curvature in the central part of thelenticular lens means 6 and 8 can be obtained by the followingexpressions.

    f1=n·r1/(n-1) . . .                               (2)

    f2=n·r2/(n-1) . . .                               (3)

Therefore, on the basis of the two factors, the remaining one factor isobtained. That is, r1=1/3 mm and r2=0.37 mm.

As shown in the figure, a divergence angle Ψ of the emitted rays afteremission from the lens means 8 is +0.135 radian. In order to furtherincrease this divergence angle, a light diffusing element may beprovided additionally on the light emitting surface of the lens means 8or in the vicinity thereof.

In this case, an angle θ1 between the propagation direction of the ray(B) which has been made incident on the central part of the lightincident surface to the associated picture element (B) and thepropagation direction of the ray (R) which has been made incident on thecentral part of the light incident surface of the lens element to theadjacent picture element (R) is 0.10 radian, and an angle θ2 between thepropagation direction of the ray (B) which has been made incident on thecentral part of the light incident surface of the lens element to theassociated picture element (B) and the propagation direction of the ray(B) which has been made incident on the end part of the light incidentsurface of the lens element to the same associated picture element (B)is 0.15 radian. Moreover, a width w of each picture element is 33 μmwhich is obtained from the relationship of w=ω/n×f1. Further, in thiscase, an array pitch P3 of the picture element sets is 3 times as largeas the array pitch P1 of the picture elements (P3=3·P1=0.3 mm).

A second embodiment of the present invention is shown in FIG. 3. Thenecessary condition for the construction of the present embodiment isthat the array pitch P3 of the picture element sets is made larger than3·P1 (P1 is the array pitch of the picture elements). In this case,P3=0.4 mm. In the figure, out of the four picture elements, one pictureelement is not used which is indicated by a mark x in the figure. Thereis shown in the figure the specific case of φ=0.15 radian, f1=1 mm andf2=1.25 mm. Further, in this case, r1=1/3 mm, r2=0.42 mm, Ψ=0.16 radian,θ1=0.1 radian and 6θ2=0.2 radian.

Incidentally, the reason for not using the picture element which isindicated by the mark x is that the positional dispersion in a valleypart between the lens elements of the light emitting side lenticularlens means is prevented from causing color irregularity. Also, thewiring pattern or the like of the liquid crystal panel may be arrangedin the position of the unused picture element indicated by the mark x.

In the present embodiment, one of every four picture elements is unused.However, the present invention is not limited thereto or thereby. Thatis, the number of unused picture elements may be increased in such a waythat, for example, two of every five picture elements are unused, orthree of every six picture elements are unused. In such cases, theresolution is degraded, but the focal length on the light emitting sidecan be made relatively large.

FIG. 4 is a horizontal sectional view showing a third embodiment of thepresent invention in which the present invention is applied to aprojection display. First, the structure of the third embodiment will bedescribed. In the figure, the reference numerals 1 and 2 designaterespectively the light source means and the three-direction means whichhave already been described.

The reference numeral 11 designates a cylindrical lens (aone-dimensional lens) for converging the rays horizontally; thereference numeral 12 designates a liquid crystal panel including themain parts 6, 7 and 8 of the fundamental embodiment of the presentinvention; the reference numeral 13 designates a cylindrical lens forconverging the rays vertically; the reference numeral 14, a projectionlens; and the reference numeral 15, a screen. In the structure of thepresent embodiment, the cylindrical lenses 11 and 13 may be omitted. Inthis case, by taking the above-mentioned divergence angle of the emittedrays from the liquid crystal panel 12, a projection lens having a largeaperture needs to be used as the projection lens 14. In any case,according to the present structure, it is obvious that the efficiency ofutilizing light can be increased up to 3 times as large as that of theprior art single panel liquid crystal projection display.

The cylindrical lens 11 for converging the rays horizontally serves toconverge the rays only horizontally. The reason why the cylindrical lens11 does not converge the rays vertically is that the contrast of theliquid crystal panel 12 depends on the vertical angle of the rays.Therefore, the function of converging the rays vertically is allotted tothe cylindrical lens 13 provided on the light emitting side of theliquid crystal panel 12.

The rays which pass through the liquid crystal panel 12 after beingconverged by the cylindrical lens 11 have a convergent inclination inthe right and left ends of the panel. Therefore, it is desirable that inthe above-mentioned embodiments, the array pitches of the lenticularlens means 6 and 8 are corrected to a certain degree. This is shown inFIG. 5.

In FIG. 5, the reference numeral 6 designates a light incident sidelenticular lens means, the reference numeral 8 designates a lightemitting side lenticular lens means, and the reference numeral 7designates only a blue picture element in the center of each of thepicture element sets. As shown in the figure, the pitch of the lightincident side lenticular lens means 6 is made larger than that of thepicture element sets, and the pitch of the light emitting sidelenticular lens means 8 is made smaller than that of the picture elementsets.

Incidentally, in FIG. 4, instead of the cylindrical lenses 11 and 13,one-dimensional Fresnel lenses may be employed. In addition, instead ofthe cylindrical lens 11, each of the mirrors 3, 4 and 5 constituting thethree-direction means 2 may be formed so as to have a concavemirror-like configuration.

Next, as the projection lens 14, a normal projection lens having arotationally symmetric configuration may be employed. However, for thepurpose of decreasing the weight and volume of the lens, a projectionlens having a pupil having a substantially rectangular shape may beemployed.

The reason for this is that in the embodiment of FIG. 3, as shown in thefigure, a horizontal light divergence angle Ψ is +0.16 radian, whichvalue is large, whereas a vertical light divergence angle issubstantially equal to the light divergence angle of the light source(0.05 radian), which value is small.

Therefore, as the projection lens, a projection lens, a pupil of whichhas a substantially rectangular shape, may be employed. The externalform of such a projection lens is shown in FIG. 6. In this case, thepupil of the projection lens is 0.05 mm in height and 0.16 mm in width.

A construction in which, as an alternative to the light emitting sidelenticular lens means 8 in the above-mentioned first and secondembodiments, double-lenticular lens means separated from the liquidcrystal panel is employed is shown in FIG. 7 as a fourth embodiment ofthe present invention. In the figure, the reference numerals 1 and 2designate respectively light source means and three-direction meanswhich are the same as those of the fundamental embodiment of FIG. 1. Thereference numeral 16 designates a liquid crystal panel which isconstructed by removing the light emitting side lenticular lens means 8from the liquid crystal panel constituted by the main parts 6, 7 and 8of FIG. 1. The reference numeral 17 designates double-lenticular lensmeans.

FIG. 8 is an enlarged detail of construction of the elements 16 and 17.In the figure, the reference numeral designates light incident sidelight lenticular lens means; the reference numeral 7 designates thepicture elements of the liquid crystal panel 16; the reference numeral8' designates a light emitting surface of the liquid crystal panel 16;the reference numeral 17, the double-lenticular lens means; thereference numeral 17', a lens surface on the light incident side of thelens means 17; the reference numeral 17", a lens surface on the lightemitting side of the lens means 17; and the reference numeral 18, blackstripes indicated by hatched lines. The black stripes serve to absorbunnecessary extraneous light. In the figure, although the black stripeshave a recessed configuration, they may have a projecting configuration.In the figure, each arrow represents the propagation direction of arespective ray. Also, a solid line, a dashed line and a corrugated linecorrespond to blue, red and green, respectively.

The function of the double-lenticular lens means 17 constituting themain part of the present embodiment will now be described.

The position of a focal plane of the light incident side lens surface17' is made to substantially coincide with the position of the lightemitting side lens surface 17". Therefore, as shown in the group of rays20 in the figure, a group of incident parallel rays are converged on thelight emitting side lens surface 17" and then diverge at a horizontaldivergence angle h. When applying the present embodiment to a directview display, if a thickness t of the double-lenticular lens means 17 isset substantially equal to a pitch P4 of the double-lenticular lensmeans 17, a value of h of about π/2 radian can be obtained. Thus, thethickness t is set to 0.3 mm.

As a result, the horizontal field or viewing angle can be increased.But, when applying the present embodiment to a projection display, thethickness t is made sufficiently larger than the pitch P4, whereby thehorizontal divergence angle h is set to a small value. A minimum valueof h is about 2.5 times as large as the above-mentioned value of φ=0.15radian, e.g., about 0.38 radian in the present numerical example in thefigure.

In FIG. 8, the position of a focal plane of the light emitting side lenssurface 17" is made to substantially coincide with the position of thelight incident side lens surface 17'. Therefore, as shown by the groupof parallel rays 19 in the figure, the rays of the primary colors whichhave been made incident to one point on the light incident side lenssurface 17' are emitted in the form of the group of parallel rays 19from the light emitting side lens surface 17". That is, the differencein direction between the incident rays of the primary colors can becompensated, and as a result, the directional characteristics of theprimary colors can be made to substantially coincide with one another.

The description of the operation of the embodiment of FIG. 8 has beencompleted.

In the first and second embodiments, it is necessary to make a distancebetween the picture elements 7 of the liquid crystal panel and the lightemitting side lenticular lens means 8 small, and it is necessary tomaintain registration therebetween. In the present fourth embodiment,this is not required. Therefore, the construction can be performed withease.

Further, in the present embodiment, a distance d between the plane ofthe picture elements and the light emitting surface 8' of the liquidcrystal panel 16 is equal to f1 (=1 mm). Thus, at the light emittingsurface 8' of the liquid crystal panel 16, the emitted rays from thepicture elements 7 diverge to the width of the pitch P3. Then, sinceP1=0.1 mm, and P3 is set 3 times as large as P1, P3=0.3 mm. Therefore,there is the advantage that it is possible to reduce moire disturbancedue to interference between the pattern of the picture elements 7 andthe pattern of the double-lenticular lens means 17.

In the present embodiment, the focal length of each of the lightincident side lens surface 17' and the light emitting side lens surface17" may be set about 0.6 to 1.5 times as large as the thickness t.Further, in order to eliminate spherical aberration, as described above,an elliptical surface having an eccentricity equal to the inverse of therefractive index n may be employed. Incidentally, in the presentembodiment, φ=0.15 radian, θ1=0.10 radian, θ2=0.15 radian, θ1'=0.10radian and Ψ=0.23 radian. The description of the fourth embodiment hasbeen completed.

FIG. 9 shows a fifth embodiment of the present invention. The purpose ofthe present embodiment is to increase the vertical field or viewingangle when applying the present embodiment to a direct view display. Apoint of difference between the present embodiment of FIG. 9 and thefourth embodiment of FIG. 8 is that in FIG. 9, transverse stripe-likelenticular lens means 21 is additionally provided between the liquidcrystal panel 16 and the double-lenticular lens means 17. The provisionof this lenticular lens means 21 allows the vertical field or viewingangle to be increased. In this case, a thickness d1 of the panel 16 is 2mm, a thickness d3 of the lens means 21 is 0.3 mm, and a thickness d2, awidth w3 and a height 13 of the lens means 17 are respectively 0.3 mm,200 mm and 150 mm.

The description of the preferred embodiments of the present inventionhas been completed. Next, variations of the preferred embodiments willbe described.

Although the white light source means 1 was used in the fundamentalembodiment of FIG. 1, alternatively, the well known three primary colorlight source means may be employed. The alternative embodiment is shownin FIG. 10. In the figure, the reference numeral 12 designates a liquidcrystal panel including the main parts 6, 7 and 8 of the fundamentalembodiment of the present invention in FIG. 1. The reference numerals22, 23 and 24 designate respectively primary color light sources ofgreen, blue and red which are arranged in parallel with one another. Thereference numeral 25 designates collimator means which is constituted bya Fresnel lens in the figure. As apparent from arrows of the raysillustrated in the figure, an angle between adjacent ones of the emittedrays of R, G and B from the collimator means 25 (corresponding to anangle which is obtained when viewing the interval between adjacent onesof the three primary color light sources 22, 23 and 24 from thecollimator means 25) is substantially equal to φ.

In FIG. 1, the first lens group means 6 was provided on the lightincident surface of the liquid crystal panel. However, the first lensgroup means 6 may be provided in the form of a panel which is outsidethe liquid crystal panel and is independent thereof. In FIG. 1, thesecond lens group means 8 was provided on the light emitting surface ofthe liquid crystal panel. However, the second lens group means 8 may beprovided inside the liquid crystal panel by the well known process ofmodulating the refractive index of a medium.

FIG. 11 shows such a variation of the main part of the first embodimentof the present invention. In the figure, the reference numeral 26designates a liquid crystal panel, and the reference numeral 27designates an independent panel which is provided independently of theliquid crystal panel 26. On the light emitting surface of theindependent panel 27, first lens group means 6 is provided.Alternatively, the first lens group means 6 may be provided on the lightincident surface of the independent panel 27. The reference numeral 28designates a light emitting side panel of the liquid crystal panel 26,and the reference numeral 29 designates a light incident side panel ofthe liquid crystal panel 26. The reference numeral 7 designates thepicture elements of the liquid crystal panel 26. The reference numerals30, 30' and 31 designate second lens group means arranged adjacent tothe plane of the picture elements 7 of the liquid crystal panel 26.

A set of small circles in FIG. 11 represent that the refractive index ofthe part indicated by the set of small circles is larger than that ofany other part. Such local modulation of the refractive index can bereadily realized by the well known ion exchange process (substitutingthallium ions for sodium ions) described in the article SPIE Vol. 892,Miniature Optics and Letters (1988), pages 3 to 11.

As shown in the figure, the function of the first lens group means 6 inFIG. 11 is the same as that of the first lens group means 6 in FIG. 1.In addition, the function of the second lens group means 30, 30' and 31in FIG. 11 is the same as that of the second lens group means 8 inFIG. 1. The description of FIG. 11 has been completed.

Instead of the one-dimensional lenticular lens means referred to in thedescription of the present invention, normal two-dimensional lensesarranged in a matrix may be employed.

In the structure of the present invention, it is possible to interchangethe horizontal direction and the vertical direction.

As set forth hereinabove, according to the present invention, it ispossible to increase the light utilization efficiency of the colorliquid crystal panel up to about 3 times as large as that of the priorart one.

I claim:
 1. A liquid crystal display having light source means andliquid crystal panel means, comprising:means for emitting rays havingwavelengths corresponding to the primary colors in respective threedirections; lens group means provided on the light incident side of saidliquid crystal panel means; and lens group means provided on the lightemitting side of said liquid crystal panel means and having a focalplane disposed outside said liquid crystal panel means; wherein anglesof propagation directions of emitted rays of the primary colors are madedifferent from one another by said primary-colors three directionemitting means, the rays of the primary colors are introduced intorespective picture elements corresponding to the primary colors by saidpanel-light incident side lens group means, and the propagationdirections of the emitted rays of the primary colors are made tosubstantially coincide with one another by said panel-light emittingside lens group means.
 2. A liquid crystal display according to claim 1,wherein said panel-light emitting side lens group means is constitutedby double-lenticular lens means which is separately arranged on thelight emitting side of said liquid crystal panel means.
 3. A liquidcrystal display according to claim 1, wherein said primary-colors threedirection emitting means is constituted by three sheets of dichroicmirrors.
 4. A liquid crystal display according to claim 1, furthercomprising projection lens means and screen means.
 5. A liquid crystaldisplay according to claim 1, wherein said light source means and saidprimary-colors three direction emitting means are constituted by threeelementary-color light source means which are arranged in parallel withone another and collimator means.
 6. A liquid crystal display accordingto claim 1, wherein said panel-light emitting side lens group means isarranged in the vicinity of a picture element forming plane in saidliquid crystal panel means.
 7. A liquid crystal display having lightsource means and liquid crystal panel means, comprising:means foremitting rays having wavelengths corresponding to the primary colors inrespective three directions; lens group means provided on the lightincident side of said liquid crystal panel means; and lens group meansprovided on the light emitting side of said liquid crystal panel means;wherein angles of propagation directions of emitted rays of the primarycolors are made different from one another by said primary-colors threedirection emitting means, the rays of the primary colors are introducedinto respective picture elements corresponding to the primary colors bysaid panel-light incident side lens group means, and the propagationdirections of the emitted rays of the primary colors are made tosubstantially coincide with one another by said panel-light emittingside lens group means; wherein said panel-light emitting side lens groupmeans is constituted by double-lenticular lens means which is separatelyarranged on the light emitting side of said liquid crystal panel means;and wherein each of focal lengths of light incident side lenticular lensand light emitting side lenticular lens constituting saiddouble-lenticular lens means is set 0.5 to 1.5 times as large as athickness thereof.
 8. A liquid crystal display including light sourcemeans and liquid crystal panel means, the liquid crystal panel meansincluding picture elements corresponding to three primary colors, thepicture elements being grouped into a plurality of sets of three pictureelements, the three picture elements in each of the sets of threepicture elements respectively corresponding to the three primary colors,the liquid crystal display comprising:three-direction means forreceiving light from the light source means, and emitting rays of thethree primary colors having three respective mutually differentpropagation directions; first lens group means, disposed before thepicture elements of the liquid crystal panel means, for receiving therays of the three primary colors from the three-direction means, anddirecting rays of the three primary colors into respective ones of thepicture elements corresponding to the three primary colors of the liquidcrystal panel means, the first lens group means including a plurality offirst lens elements equal in number to the sets of three pictureelements, each of the lens elements corresponding to a respective one ofthe sets of three picture elements; and second lens group means,disposed after the first lens group means and having a focal planedisposed at a position of the first lens group means, for receiving raysof the three primary colors having three respective mutually differentpropagation directions from one of (1) the first lens group means and(2) the picture elements of the liquid crystal panel means, and emittingrays of the three primary colors having three respective propagationdirections substantially coinciding with one another, the second lensgroup means including a plurality of second lens elements equal innumber to the sets of three picture elements, each of the second lenselements corresponding to a respective one of the sets of three pictureelements.
 9. A liquid crystal display according to claim 8, wherein thethree-direction means includes three sheets of dichroic mirrors.
 10. Aliquid crystal display according to claim 8, wherein the three pictureelements in each of the sets of three picture elements are disposed at afirst predetermined pitch; andwherein the sets of three picture elementsare disposed at a second predetermined pitch, the second predeterminedpitch being greater than three times the first predetermined pitch. 11.A liquid crystal display according to claim 8, furthercomprising:projection lens means disposed after the second lens groupmeans; and screen means disposed after the projection lens means.
 12. Aliquid crystal display according to claim 11, wherein the projectionlens has a pupil having a substantially rectangular shape.
 13. A liquidcrystal display according to claim 8, further comprising:projection lensmeans disposed after the second lens group means; screen means disposedafter the projection lens means; first one-dimensional light convergingmeans disposed before a light incident side of the liquid crystal panelmeans for converging light in a first direction; and secondone-dimensional light converging means disposed after a light emittingside of the liquid crystal panel means for converging light in a seconddirection perpendicular to the first direction.
 14. A liquid crystaldisplay according to claim 8, wherein the light source means includesthree primary color light sources for respectively emitting rays of thethree primary colors; andwherein the three-direction means includescollimator means for receiving the rays of the three primary colors fromthe three primary color light sources and emitting rays of the threeprimary colors having three respective mutually different propagationdirections.
 15. A liquid crystal display according to claim 8, whereinthe second lens group means is disposed in the liquid crystal panelmeans adjacent to a plane in which the picture elements of the liquidcrystal panel means are disposed.
 16. A liquid crystal display includinglight source means and liquid crystal panel means, the liquid crystalpanel means including picture elements corresponding to three primarycolors, the liquid crystal display comprising:three-direction means forreceiving light from the light source means, and emitting rays of thethree primary colors having three respective mutually differentpropagation directions; first lens group means, disposed before thepicture elements of the liquid crystal panel means, for receiving therays of the three primary colors from the three-direction means, anddirecting rays of the three primary colors into respective ones of thepicture elements corresponding to the three primary colors of the liquidcrystal panel means; and second lens group means, disposed after thefirst lens group means, for receiving rays of the three primary colorshaving three respective mutually different propagation directions fromthe picture elements of the liquid crystal panel means, and emittingrays of the three primary colors having three respective propagationdirections substantially coinciding with one another, the second lensgroup means including double-lenticular lens means disposed after alight emitting side of the liquid crystal panel means, thedouble-lenticular lens means including a first lenticular lensconstituting a light incident side of the double-lenticular lens meansand having a focal length about 0.5 to 1.5 times as large as a thicknessof the double-lenticular lens means, and a second lenticular lensconstituting a light emitting surface of the double-lenticular lensmeans and having a focal plane disposed at a position of the firstlenticular lens.